Conventionally, there has been known an in-vehicle air conditioning apparatus that improves heating capability of an air conditioning unit by taking in air heated by heat exchange with a battery into the air conditioning unit (see, Patent Literature ((hereinafter, abbreviated as PTL) 1, for example).
Specifically, the in-vehicle air conditioning apparatus of PTL 1 is provided with an airflow passage for allowing the air to flow to the battery. One end of the airflow passage is opened at the rear of a vehicle interior, and the other end thereof is connected to the air conditioning unit at the front of the vehicle interior. Therefore, when the air sent out from the air conditioning unit flows through the rear of the vehicle interior is drawn from the one end of the airflow passage, and passes by the battery. At this time, the air is heated by heat exchange with the battery. Thereafter, the heated air is returned to the air conditioning unit, and is sent out to the vehicle interior again after temperature control.